Tube shield



March 3, 1959 0N 2,876,276

TUBE SHIELD Filed Oct. 26, 1956 I N VE N TOR (Lynn B. jlfE'Llvfl BY Q5550,

ATTORNEYS TUBE SHIELD Clyde R. Melton, Atlanta, Tex., assignor to North Texas Mfg. Corp, Atlanta, Tex., a corporation of Texas Application October 26, 1956, Serial No. 618,582

2 Claims. (Cl. 174-35) This invention relates to tube shields and particularly to improved, inexpensive, unitary shields especially adapted for use with miniature tubes, and to methods for manufacturing the same.

The invention provides an extremely simple tube shield construction and a method for manufacturing the same from a one-piece sheet metal blank. In this connection, the invention is directed to a tube shield construction and method such that the shield body, the mounting means therefor and resilient means for engaging the tube with which the shield is associated are all fabricated by simple steps as an integral unit.

The invention is further characterized by the provision of a tube shield, and method for making the same as an integral unit from a sheet metal blank, including a plurality of circumferentially spaced inwardly directed spring fingers for engaging the tube with which the shield is to be associated, certain of said fingers being specially oriented on the sheet met-a1 body of the shield in areas which are mechanically reinforced by reason of the coufiguration of the devices.

In order that the invention may be readily understood in detail, reference is made to the accompanying drawings, which form a part of this specification, and wherein:

Fig. 1 is a view in perspective of a completed tube shield constructed in accordance with the invention;

Fig. 2 is a top view of the device shown in Fig. l, and

Fig. 3 is a plane view of a sheet metal blank from which the tube shield of Fig. 1 is fabricated.

Referring now to the drawings in detail, it will be seen that the tube shield there illustrated comprises a generally tubular body 1, of circular cross-section in this embodiment of the invention. At its lower end, the body is provided with a plurality of circumferentially spaced mounting ears 2, 3 lying substantially in the transverse plane defined by the bottom end of the body. The mounting ears 2 and 3 are provided with apertures 4 and 5, respectively, to receive sheet metal screws or other fastening elements. At points spaced circumferentially about the device, the body is provided with axially extending, inwardly offset, tube-engaging spring fingers 6, 7 and 8.

The device of Figs. 1 and 2 is fabricated from the thin sheet metal blank illustrated in Fig. 3. The blank A is in the form of a greatly elongated rectangle with a plurality of spaced extensions provided along one long side thereof to form a series of mounting ears. The series of mounting ears may be considered, for clarity of reference, as made up of successive groups of ears with two ears in each group, as at 2, 3 and 2, 3'. The ears of each such group are spaced by a distance B, and the first ear of each group is spaced from the second car of the preceding group by a distance C substantially larger than the distance B. This diiference in spacing is continued throughout the series.

The blank A is further provided, as by a stamping operation, with a series of spaced fingers, which will become the fingers 6-8 of the final device. The series nited States Patent of fingers may be considered, for clarity of reference, as made up of successive groups of three fingers each, as at 8, 6, 7 and 8', 6, 7'. The first and second finger of each group of fingers are spaced apart by a distance D and the second and third finger of each group by a larger distance E, the spaces D and B being so related to the space B that the first finger 8 of the series is disposed relatively closely to end 9 of the blank. Similarly, finger 8 is disposed relatively close to the cutting line 9 along which the blank is to be severed. The third finger of each group is disposed in an area of the blank adjacent the second ear of the corresponding group of spaced mounting ears. Thus, finger 7 is disposed adjacent mounting ear 3.

The fingers 6-8 are each formed by cutting the material of blank A along three sides only of a narrow rectangle extending transversely of the blank. This may be accomplished by a simple stamping operation, at the same time that the sheet metal blank is initially formed, the stamping operation being of such nature that the fingers 6-8 are ofiset from the plane of the blank, with all. the fingers being offset in the same direction. Such stamping operation is advantageously so carried out that the main body portions of the fingers 6-8 are spaced from the plane of the blank by a distance at least equal to the thickness of the sheet metal of the blank. It will be understood that each finger 6-8 thus joins body 1 only at one end of the finger. Advantageously, the fingers join the body of the blank at what will be their upper ends, as viewed in Fig. 1.

Operating in accordance with a preferred embodiment of the invention, a blank of the general form seen in Fig. 3 is first formed in a single operation. That is, a single die is employed to form the series of extensions or cars 2 and 3 and the series of spring fingers 6, 7 and 8. The blank so produced is of such length as to provide sufiicient sheet metal for a plurality of tube shields. Either as a part of the initial step, or as a separate operation, the blank is severed along transverse lines, as indicated at ,9, to provide individual tube shield blanks. Each such individual blank is then bent upon itself to provide the general tubular construction seen in Fig. 1, with ends 1* and 1 overlapping and in face-to-face contact.

Referring to Figs. 2 and 3, it will be seen that, because of the particular spacing of the spring fingers 6-8 on the initial blank, the bending operation just mentioned causes finger 8 to be positioned in the area of the overlapping ends 1 and 1 of the sheet metal body 1. With the portion 1 being bent to substantially the same curvature as the remainder of the body, it will be seen that, when spring finger 8 engages a tube within the shield, the resilient action of the spring finger serves to maintain the overlapping ends 1 and 1 in firm and substantially uniform face-to-face contact.

As a final operation the mounting ears 2 and 3 are bent outwardly into the form seen in Fig. 1. Such bending operation causes the ends 2 and 3 each to join the body 1 along a substantially straight line, as seen at 10 in Fig. 1, so distorting the adjacent portions of body 1 to provide flattened side areas, as seen at 11, Fig. 1.

Referring to Fig. 2, it will be noted that, while spring finger 6 is distant from both of the mounting ears and from the overlapping ends 1 and 1 spring finger 7 is disposed immediately adjacent to mounting ear 3. Thus, spring finger 7 is positioned in an area of the body which is stifiened by reason of the distortion of the body brought about when ear 3 is bent outwardly to its final position.

Spring finger 8 is also located in a stiffened area proa third mounting ear, positioned adjacent spring finger 6, may advantageously be provided.

Iclaim: 1. A unitary tube shieldcomprisinga sheet metal member ofgenerally rectangular plan curving upon itself with ends overlapping to form a generally tubular body and provided with a plurality of integral tube-engaging spring fingers spaced circumferentially about and extending axially of said body, each such finger being radially inwardly offset with respect to said body and joining the same only at one end of the finger, one of said fingers being located on the innermost one of said overlapping ends of said member, said member being further provided with a plurality of mounting earsintegral therewith, said mounting ears being spaced circumferentially with respect to said body and lying substantially in a plane defined by one end of said body, each of said ears joining said member in a straight-line bend and said member having fiat areas each'contiguous with one of said straightline bends.

2. A tube shield constructed in accordance with claim 1 and wherein a second of said fingers is located adjacent the junction between one of said mounting ears and said body.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Subminiature Tube Sockets and Shields, published in Electrical Manufacturing, October 1952 (page 166 relied (Copy in the Scientific Library and Div. 69, class 

